Internal-combustion engine



H. HAAS.

INTERNAL COMBUSTION ENGINE.

APPLICATION FILED MAR,19, 1920.

Patented Jan. 18, 1921.

UNITED STATES PATENT OFFICE.

HERBERT HAAS, or LONG BEACH, CALIFORNIA, ASSIGNOR 0F ONE-HALF To WILLIAM L. KANN, 0F PITTSBURGH, PENNSYLVANIA.

Specification of Letters Patent.

Patented Jan. 18, 1921.

Application filed March 19, 1920. Serial No. 367,188.

Toall'whom z'fimay concern: i

Be it known that I, HERBERT HAAS, res ding at Long Beach, county of'Los. Angeles,

-.and State of California, have invented a new and useful Improvement in Internal Combustion Engines, of which the following is a full, clear,'and exact description, reference being had to the accompanying drawing, forming part of this specification, in which- The figure is a sectional diagrammatic view of a two cycle oil-burning engine embodying my invention and also showing one form of air pump or compressor in connection therewith. I

My invention has relation to internal combustion engines and more particularly to engines of the Diesel type. The power which an engine of this type is capable of developing depends upon the amount of air which is available for combustion. My invention is designed to provide improved means for introducing air into. the engine cylinder in a manner which will result in not only thorough scavenging, but, also surcharging of the working cylinder with fresh air, thereby permitting great overloads on the engine. The invention is also designed .to provide means which will secure these results with a minimum expenditure of power for supplying scavenging and charging air. The nature of my invention will be more clearly understood byreference to the accompanying drawing, in which I have illustrated one embodiment thereof, and which will now be described, it being premised, however, that various changes may be made in the details of construction, arrangement and combination of the various parts, without departing from the spirit and scope of invention, as defined in the appended claims.

In these drawings, the numeral 1. designates the water-jacketed working cylinder of the oil engine; 2 the piston; 3 the connecting rod, and 4 the crank. 5 is the water-- cooled head. v 6 designates the exhaust ports; 7 the scavenging ports; 8 the combined scavenging and air-charging ports and 9 the surcharging ports. I The exhaust ports 6 and the scavenging ports '7 are arranged to be covered and uncovered'by the piston 2. The ports 8 and 9 are opened and closed by means of a double piston valve whose stem 10 is actuated in any suitable manner in proper timed relation to the movements of the piston by an eccentric 11, on a shaft'12, suitably geared to the engine crank shaft. The valve stem 10 carries a valve member 13, which controls the ports 8, and has another valve member 14, loosely seated on the stem and supported by a spring 15, which acts to normally hold the valve closed. The valve is opened by means of a tappet 16, adjustably secured on the stem 10.

The numerals 17, 18 and 19 designate, respectively, the low pressure cylinder, intermediate cylinder and high pressure cylinder of a three-stage air pump or compressor. For illustrative purposes, I have shown this pump as an independently driven one, but it may be driven from the engine shaft or in any other well known manner. I have also illustrated an air compressor of the reciprocatmg type, but it will be understood that any other suitable type, such as a multistage rotary or air turbine compressor may be used.

The low pressure cylinder 17 is arranged to deliver air to the scavenging ports 7. The intermediate cylinder 18 is arranged to deliver to the ports 8 under the control of the valve member 13. The high pressure cylinder 19 is arranged to deliver to the ports 9 under the control of the valve member 14:.

The operation is as follows: When the piston 2 approaches its outer dead center, the products of combustion begin to be expelled through the exhaust ports 6, by reason of the fact that the pressure of such products is still above atmospheric pressure. As

soon as the ports 7 commence to be uncov-' ered, scavenging air is admitted from the its exhaust gases. A portion of the scavenging, therefore, takes place during the instroke and the scavenging action is prolonged during the outstroke by the fact that the valve 13 will be opened to render the ports 8 effective after ports 7 have been closed and ports 6 are still open.

Before the ports 6 are completely closed by the returning piston on its outstroke, a portion of the scavenging air admitted through the ports 8 is employed for purging the cylinder of the; last traces of exhaust gases, the ports 7 having in the meantime been closed by the piston. Air will continue action at will.

to be admitted to the cylinder through the ports 8 after the exhaust ports 6 are completely closed by the piston, thus filling the cylinder space with fresh air. As the piston 2 approaches the surcharging ports 9, the valve member 14 is opened by the tappet l6, and a fresh charge of high pressure air is thus admitted into the cylinder space. The tappet 16 is made adjustable, so that. the opening of the valve 14 can be timed as may be desired. This adjustment may be of a nature to bring the valve 14 into or out of Both valve members 13 and 14 will remain open until the piston 2 passes the ports 8 and 9, and closes such ports, thereby stopping the flow of air into the cylinder. The valves 15 and 16 will then be radually closed.

The advantages of my invention are manifold. For the purpose of purging the cylinder of its exhaust gases, air at relatively low pressure is used. Low pressure air is not only useful for this purpose, in that it is provided with a minimum expense of power, but it scavenges more thoroughly than does high .pressure air. To complete the scavenging and furnish the charging air, a slightly higher pressure is provided. .Finally, if it 15 desired to provide for an overload, air of still higher pressure is forced into the end of the cylinder through the surcharging ports. Inasmuch as the power of the engine is limited by the amount of the oxygen in the air made available in the working cylinder to burn the fuel oil injected into it, this surcharging enables additional oil to be burned, and thus increases the power output per cylinder.

A similar result might be obtained without the use of the valve member 14 by forcing the high pressure surcharging air through the port 8. This practice, however, would be wasteful in that a portion of such high pressure air would be expelled with the exhaust gases through the port 6; and as above stated, air at such high pressure is not an eflicient scavenging medium. In the reexpansion of this air to the pressure of the air in the working cylinder, power would be wasted, By the three-tier port construction above described, successively higher pressures of the scavenging, charging and surcharging air are provided, corresponding to the increased pressures produced by the advancing piston during the compression stroke. In this manner, little of the power used in compressing the air is wasted by reexpansion of the air to the existing pressure in the cylinder atthe moment.

If it is desired to operate the engine with partial loads only, then the valve 14 may be cut out of action entirely. In this case, the air delivered through the valve 13 will be suflicient: to operate the engine. During periods of maximum load demands, the

valve 14 may be put into action for the purpose described. i

I claim: p

1. An internal combustion engine having means for exhausting the products of combustion, means for admitting low pressure air for scavenging while the exhaust is operating, means for admitting air at a slightly higher pressure into the cyllnder during the compression stroke and before the exhaust is completed, and still other means for admitting air at a stillhigher pressure on the compression stroke and during a relatively late period in said stroke for surcharging the cylinder, substantially as described.

2. An internal combustion engine having exhaust ports arranged to be opened and closed by the working piston, two sets of scavenging ports, one of said sets being wholly controlled by said piston and the other set of such ports operating partly as scavenging and partly as charging ports after the first scavenging ports cease to function, and' a third set of air inlet ports for surcharging the cylinder during a relatively late period in the compression stroke, substantially as described.

3. An internal combustion engine having exhaust ports and three sets of air inlet ports arranged to come into action at different.

points of the stroke of the piston, a source of relatively low pressure air connected to the first set of'such ports, a source of relatively higher pressure air connected to the second set of such ports, and-a source of still higher pressure air connected to the third set of such ports, together with means for controlling the-inlet ports to render them respectively eflective at three different periods in the compression stroke, substantially as described.

4. An internal combustion engine-having exhaust ports and three sets of air inlet ports arranged. to come into action at different points of the compression stroke of the piston, a source of-relatively low pressure air connected to the first set of such ports, a source of relatively higher pressure air connected to the second set of such ports, and a source of still higher pressure air connected to the third set of such ports, together with mechanically operated valves for opening the second and third set of such ports, the first set being controlled by the engine piston which is also arranged to cut off the air admission through the second and third set of ports, substantially as described.

-5. An internal combustion engine having exhaust ports located at the inner end of its working cylinder, scavenging ports located in the cylinder wall opposite the exhaust ports, a second tier of ports beyond the first scavenging ports, and a third tier of ports beyond the second tier to become effective during a late period of the compression stroke, the exhaust ports and the first tier of air ports being wholly controlled by the engine piston in both opening and closing, and mechanical valves for controlling air admission through the ports of the second and third tiers, the piston also operating to cut ofif the flow of air through the ports of the second and third tiers, substantially as described.

6. An internal combustion engine having its cylinder provided with exhaust ports, a tier of air ports controlled solely by the working piston of the engine for admitting low pressure air to the cylinder for scavenging, a second tier of air ports in the cylinder. Wall beyond the first tier for admitting air at a slightly higher pressure for scavenging and charging the working cylinder, a third tier of air ports in the cylinder wall beyond the second tier for admitting air at a still higher pressure for surcharging the cylinder, the expulsion of exhaust gases through the exhaust ports and the admission of low pressure for scavenging being controlled wholly by the working piston, together with mechanically operated valves for opening the ports of the second and third tiers to thereby successively admit air pressure into the cylinder during the compression stroke, the flow into the cylinder through the ports of the second and third tiers being closed by the advancing movement of the piston, said valves having means whereby they are closed after the piston has closed the second and third tiers of ports, substantially as described.

7. An internal combustion engine, having its cylinder provided with an exhaust port, and with three separate sets of inlet ports arranged at different distances out from the crank shaft end of the cylinder, three separate sources of air supply'at diiferent pressures, connected respectively to the three sets of ports, and means for controlling said ports, whereby air from the source of lowest pressure is admitted to the cylinder while the exhaust port is open, air from the source of intermediate pressure is admitted partly while the exhaust port is opened and partly after it is closed on the compression stroke, and air from the source of highest pressure is thereafter admitted during a relatively late period in the compression stroke, substantially as described.

In testimony whereof I have hereunto set my hand.

HERBERT HAAS. 

